Neural modulation system

Abstract

A neural modulation system includes neural encoder in a patient-external device. The neural encoder converts input signals into a neural stimulation pattern and wirelessly transmits the neural stimulation pattern to a patient-internal device. The patient internal device includes a flexible substrate and a two dimensional array of neural probes disposed on the flexible substrate. Each neural probe includes an array of magnetic neural stimulators and/or an array of neural sensors along with probe addressing circuitry that allow for addressing the magnetic neural stimualtors and/or neural sensors. Control circuitry in the implantable device controls activation of the magnetic neural stimulators and/or neural sensors according to the neural stimulation pattern via the probe addressing circuitry.

The invention claimed is: 
     
       1. A vision prosthetic system, comprising:
 a camera configured to provide camera signals in response to images; 
 a patient-external device comprising:
 a neural encoder programmed to convert the camera signals into a neural stimulation pattern; and 
 communication circuitry configured to wirelessly transmit the stimulation pattern to a patient-internal device configured to be disposed within a cranium of a patient; 
 
 the patient-internal device comprising:
 communication circuitry configured to wirelessly receive the stimulation pattern from the patient-external device; 
 an implantable neural subsystem, comprising:
 a flexible substrate; 
 a two dimensional array of neural probes disposed on the flexible substrate, the neural probes configured to stimulate and sense neurons, each neural probe comprising:
 an array of magnetic neural stimulators configured to magnetically stimulate neurons; 
 an array of neural sensors configured to sense neural signals of the neurons; and 
 probe addressing circuitry comprising thin film switches; and 
 
 
 control circuitry configured to control activation of the magnetic neural stimulators and neural sensors according to the neural stimulation pattern via the probe addressing circuitry. 
 
 
     
     
       2. The system of  claim 1 , wherein the magnetic neural stimulators comprise three dimensional coils. 
     
     
       3. The system of  claim 2 , wherein each probe comprises about 250 to about 450 three dimensional coils. 
     
     
       4. The system of  claim 2 , wherein the three dimensional coils have a stress gradient that causes loops of the coils to curl out of plane. 
     
     
       5. The system of  claim 1 , wherein each probe has a three dimensional shape such that an exterior surface of the probe comprises at least a portion of a first surface of the flexible substrate and an interior surface of the probe comprises at least a portion of a second surface of the flexible substrate. 
     
     
       6. The system of  claim 5 , wherein the three dimensional shape of each probe is a cylinder. 
     
     
       7. The system of  claim 6 , wherein each cylinder has a diameter of about 30 to about 100 μm and a length of about 1.4 to about 2 mm. 
     
     
       8. The system of  claim 1 , wherein:
 each probe comprises a probe area of the flexible substrate; and 
 the flexible substrate is a multi-layered stress-engineered structure at least in the probe area. 
 
     
     
       9. The system of  claim 8 , wherein, when laid flat, each probe area of the flexible substrate has a surface area of about 0.0048 cm 2  to about 0.032 cm 2 . 
     
     
       10. The system of  claim 8 , wherein a bridge of the flexible substrate attaches each probe area to other areas of the flexible substrate. 
     
     
       11. The system of  claim 10 , wherein each probe is disposed at an angle to the other areas of the flexible substrate at the bridge. 
     
     
       12. The system of  claim 1 , wherein the neural sensors are disposed on an exterior surface of the probe and the neural probe addressing circuitry is disposed on an interior surface of the probe. 
     
     
       13. The subsystem of  claim 1 , wherein:
 the flexible substrate has a distal region, a proximal region, and a center region extending between the distal region and the proximal region; and 
 the neural probes are disposed at the distal region of the flexible substrate; and 
 further comprising an interface area disposed at the proximal region of the flexible substrate, the interface region configured to electrically couple the probe addressing circuitry to the control circuitry. 
 
     
     
       14. The system of  claim 1 , wherein the neural probes are configured to penetrate into the visual cortex to at least the 5 th  cortical layer. 
     
     
       15. A method comprising:
 generating camera signals in response to an image; 
 mapping the camera signals to a neural stimulation pattern that represents the image; 
 wirelessly transmitting the neural stimulation pattern to a body-implantable device that includes an array of magnetic neural stimulators; and 
 magnetically stimulating neurons of the visual cortex according to the neural stimulation pattern. 
 
     
     
       16. The method of  claim 15 , further comprising:
 sensing the neurons of the visual cortex using an array of electrical neural sensors; and 
 adjusting the neural stimulation pattern based on the sensing. 
 
     
     
       17. The method of  claim 15 , wherein magnetically stimulating comprises magnetically stimulating the visual cortex at a resolution of about 15 μm to about 25 μm. 
     
     
       18. The method of  claim 15 , wherein magnetically stimulating comprising controlling current to magnetic neural stimulators comprising three dimensional coils. 
     
     
       19. The method of  claim 18 , wherein controlling current through the three dimensional coils comprises controlling one or more of phase, frequency, duty cycle, and amplitude of the current pulses to the three dimensional coils. 
     
     
       20. The method of  claim 15 , wherein magnetically stimulating the neurons comprises magnetically stimulating to predominantly activate neurons in a single orientation while minimally activating neurons in other orientations or not activating neurons in other orientations. 
     
     
       21. A neural modulation system, comprising:
 a patient-external device comprising:
 a neural encoder programmed to convert input signals into a neural stimulation pattern; and 
 communication circuitry configured to wirelessly transmit the stimulation pattern to a patient-internal device configured to be disposed within a cranium of a patient; 
 
 the patient-internal device comprising:
 communication circuitry configured to wirelessly receive the stimulation pattern from the patient-external device; 
 an implantable neural subsystem, comprising:
 a flexible substrate; 
 a two dimensional array of neural probes disposed on the flexible substrate, the neural probes configured to stimulate and sense neurons, each neural probe comprising:
 an array of magnetic neural stimulators configured to magnetically stimulate neurons; 
 an array of neural sensors configured to sense neural signals of the neurons; and 
 probe addressing circuitry comprising thin film switches; and 
 
 
 control circuitry configured to control activation of the magnetic neural stimulators and neural sensors according to the neural stimulation pattern via the probe addressing circuitry.